Spinal fixation systems with bifurcated connectors

Abstract

A system and method to form a surgical construct using spinal rods and bifurcated connectors. One or more spinal rods such as those used in fusing vertebrae of the spine are attached with the bifurcated connectors to form the surgical construct. The bifurcated connector may be used with pedicle screws, lamina clamp assemblies or vertebra hook assemblies for installation of the surgical construct adjacent to selected portions of the patient's spine. A cap or end closure cooperates with an associated deformable coupling to position the spinal rod within the bifurcated connector. The spinal fixation system may consist of a pair of rods installed on opposite sides of the spine or a single midline spinal rod. The connectors and their associated mechanism for attaching instrumentation to the patient's spine are readily adaptable for use with either parallel rods on opposite sides of the patient's spine or a single midline spinal rod fixation system.

What is claimed is: 
     
       1. A vertebra hook assembly for releasably attaching spinal instrumentation having a deformable coupling to selected portions of a patient's spine comprising: a connector body having an opening extending partially therethrough and sized to receive a portion of the spinal instrumentation therein;   a hook extending from the connector body opposite from the opening;   a recess formed within the opening to receive the deformable coupling carried by the spinal instrumentation;   an end closure for blocking the opening in the connector body after the spinal instrumentation and deformable coupling have been disposed therein;   the connector body having a generally cylindrical configuration with the opening extending partially therethrough;   a pair of slots formed in the connector body and communicating with the opening to allow installation of the spinal instrumentation therein;   the lower portion of the opening having spherical surfaces which partially define the recess and correspond to spherical surfaces on the exterior of the deformable coupling; and   threads formed above the spherical surfaces on the interior of the opening for engagement with the end closure.   
     
     
       2. The vertebra hook assembly as defined in claim 1 further comprising: the end closure having a generally cylindrical configuration with threads formed on a portion of its exterior for engagement with the threads on the interior of the opening;   an annular groove formed in the end closure to receive a cylindrical portion of the connector body therein; and   means for engaging the end closure with a surgical tool for tightening the end closure with the connector body and the deformable coupling.   
     
     
       3. The vertebra hook assembly as defined in claim 2 wherein the end closure further comprises: a contoured surface on the portion of the end closure contained within the opening; and   the contoured surface on the end closure corresponding to the exterior surface of the deformable coupling.   
     
     
       4. A lamina clamp assembly for releasably attaching spinal instrumentation to selected portions of a patient's spine comprising: a connector body having an opening extending partially therethrough and sized to receive a portion of the spinal instrumentation therein;   a first hook extending from the body opposite from the opening;   a recess formed within the opening to receive a deformable coupling carried by the spinal instrumentation;   an end closure for blocking the opening in the connector body after the spinal instrumentation and deformable coupling have been disposed therein;   a second hook slidably disposed within the opening in the connector body adjacent to the first hook; and   means for releasably securing the second hook spaced from the first hook.   
     
     
       5. The lamina clamp assembly as defined in claim 4 further comprising the first and second hooks each having an end spaced from the connector body and partially defining a gap sized to receive a selected portion of the vertebrae therebetween. 
     
     
       6. The lamina clamp assembly as defined in claim 5 wherein each hook further comprises a bifid end. 
     
     
       7. The lamina clamp assembly as defined in claim 4 further comprising: the connector body having a generally cylindrical configuration with the opening extending partially therethrough;   a pair of slots formed in the connector body and communicating with the opening to allow installation of the spinal instrumentation therein;   the lower portion of the opening having spherical surfaces which partially define the recess and correspond to spherical surfaces on the exterior of the deformable coupling; and   a first set of threads formed above the spherical surfaces on the interior of the opening for engagement with the end closure.   
     
     
       8. The lamina clamp assembly as defined in claim 7 further comprising: the end closure having a generally cylindrical configuration with threads formed on a portion of its exterior for engagement with the first set of threads on the interior of the opening;   an annular groove formed in the end closure to receive a cylindrical portion of the connector body therein; and   means for engaging the end closure with a surgical tool for tightening the end closure with the connector body and the deformable coupling.   
     
     
       9. The lamina clamp assembly as defined in claim 8 wherein the end closure further comprises: a contoured surface on the portion of the end closure contained within the opening; and   the contoured surface on the end closure corresponding to the exterior surface of the deformable coupling.   
     
     
       10. The lamina clamp assembly as defined in claim 4 wherein the means for releasably securing the second hook further comprise: a set of threads found within the opening immediately adjacent to the second hook;   a plug having one end for engagement with the second hook and threads on the exterior of the plug for engagement with the set of threads within the opening; and   means for engaging the plug with a surgical tool for securing the second hook to the connector body with the plug.   
     
     
       11. The lamina clamp assembly as defined in claim 10 wherein the plug further comprises a spherical portion on the other end of the plug opposite from the second hook and the spherical portion sized to engage the exterior of the deformable coupling. 
     
     
       12. The lamina clamp assembly as defined in claim 4 wherein the second hook further comprises: a plate slidably disposed within the opening; and   a pair of curved fingers extending from the plate and partially defining a gap sized to engage a portion of the lamina within the fingers.   
     
     
       13. A spinal fixation system having instrumentation for fusing selected portions of a patient's spine comprising: a plurality of connectors for attaching the instrumentation to selected portions of the patient's spine;   each connector having a body with an opening extending partially therethrough for engagement with the instrumentation;   one group of connectors having means for attachment to the selected portions of the patient's spine;   at least two other connectors having arms extending from each respective connector body to allow attaching the instrumentation along the midline of the patient's spine;   a plurality of deformable couplings carried by the instrumentation and a recess formed within the opening of each connector body to receive one of the deformable couplings;   each deformable coupling having a slot extending partially therethrough;   an end closure for blocking the opening in each connector body after the instrumentation and associated deformable coupling have been disposed therein; and   the instrumentation further comprising an elongated member with the deformable couplings slidably disposed on the exterior of the elongated member.   
     
     
       14. The spinal fixation system as defined in claim 13 wherein each deformable coupling further comprises: a bore extending therethrough and sized to receive the elongated member therein; and   the slot formed in the exterior of the deformable coupling and communicating with the bore.   
     
     
       15. The spinal fixation system as defined in claim 13 wherein the elongated member comprises a spinal rod. 
     
     
       16. The spinal fixation system as defined in claim 13 wherein one or more of the connectors further comprise: a hook extending from the connector body opposite from the opening; and   the hook having an end spaced from the connector body partially defining a gap to receive a selected portion of a vertebrae therebetween.   
     
     
       17. The spinal fixation system as defined in claim 13 wherein one or more of the connectors further comprise a threaded shank extending from the connector body opposite from the opening and the threaded shank providing the means for attaching the respective connector to the selected portion of the patient's spine. 
     
     
       18. The spinal fixation system as defined in claim 13, further comprising a plurality of elongated members having at least one of the deformable couplings slidably disposed on the exterior of each elongated member. 
     
     
       19. A spinal fixation system having instrumentation for fusing selected portions of a patient's spine comprising: a plurality of connectors for attaching the instrumentation to the patient's spine;   each connector having a body with an opening extending partially therethrough for engagement with the instrumentation;   the connectors having means for attachment to the selected portions of the patient's spine:   a plurality of deformable couplings carried by the instrumentation and a recess formed within the opening of each connector body to receive one of the deformable couplings;   each deformable coupling having a slot extending partially therethrough;   an end closure for blocking the opening in each connector body after the instrumentation and associated deformable coupling have been disposed therein;   a first hook extending from the connector body opposite from the opening;   a second hook slidably disposed within the opening in the connector body adjacent to the first hook; and   means for releasably securing the second hook spaced from the first hook.   
     
     
       20. The spinal fixation system as defined in claim 19 wherein each connector further comprises: a first set of threads formed within the opening for engagement with the end closure;   a second set of threads formed within the opening immediately adjacent to the second hook;   a plug having threads on its exterior for engagement with the second set of threads within the opening; and   means for engaging the plug with a surgical tool for securing the second hook to the connector body with the plug.   
     
     
       21. The spinal fixation system as defined in claim 20 wherein the plug further comprises a spherical portion on the end opposite from the second hook and the spherical portion sized to engage the exterior of the deformable coupling. 
     
     
       22. A spinal fixation system having instrumentation for fusing selected portions of a patient's spine comprising: a plurality of connectors for attaching the instrumentation to the midline portion of the patient's spine;   each connector having a body with an opening extending partially therethrough for engagement with the instrumentation;   a plurality of deformable couplings carried by the instrumentation;   a recess formed within the opening of each connector body to receive one of the deformable couplings;   an end closure for blocking the opening in each connector body after the instrumentation and associated deformable coupling have been disposed therein; and   wherein one of the connectors further comprises a pair of arms projecting laterally from the connector body.   
     
     
       23. A spinal fixation system having instrumentation for fusing selected portions of a patient's spine comprising: a plurality of connectors for attaching the instrumentation to selected portions of the patient's spine;   each connector having a body with an opening extending partially therethrough for engagement with the instrumentation;   the connectors having means for attachment to the selected portions of the patient's spine;   a plurality of deformable couplings carried by the instrumentation;   a recess formed within the opening of each connector body to receive one of the deformable couplings;   each deformable coupling having a slot extending partially therethrough;   an end closure for blocking the opening in each connector body after the instrumentation and associated deformable coupling have been disposed therein;   each connector body having a generally cylindrical configuration with the opening extending partially therethrough;   a pair of slots formed in each connector body and communicating with the respective opening to allow installation of spinal instrumentation therein;   at least four connectors with means for attachment to selected portions of the patient's spine spaced longitudinally and laterally from each other;   at least two connectors having a pair of arms projecting laterally from the respective connector bodies;   a deformable coupling slidably disposed on each arm and sized to be received within the opening of the connectors with the means for attachment to selected portions of the patient's spine; and   an elongated member having at least two deformable couplings slidably disposed on the exterior thereof and sized to be received within the openings of the connectors with the pair of arms.   
     
     
       24. The spinal fixation system as defined in claim 23 wherein the elongated member comprises a spinal rod. 
     
     
       25. The spinal fixation system as defined in claim 23 further comprising a vertebra hook assembly disposed on the elongated member intermediate the ends the thereof. 
     
     
       26. The spinal fixation system as defined in claim 23 further comprising a lamina clamp assembly disposed on elongated member intermediate the ends thereof. 
     
     
       27. A spinal fixation system having instrumentation for fusing selected portions of a patient's spine comprising: a plurality of connectors for attaching the instrumentation to the midline portion of the patient's spine;   each connector having a body with an opening extending partially therethrough for engagement with the instrumentation;   an end closure for blocking the opening in each connector body after the instrumentation has been disposed therein; and   wherein one of the connectors further comprises a pair of arms projecting laterally from the connector body.   
     
     
       28. A spinal fixation system having instrumentation for fusing selected portions of a patient's spine comprising: a plurality of connectors for attaching the instrumentation to the midline portion of the patient's spine;   each connector having a body with an opening extending partially therethrough for engagement with the associated instrumentation;   an end closure for blocking the opening in each connector body after the instrumentation has been disposed therein;   each connector body having a generally cylindrical configuration with the opening extending partially therethrough;   a pair of slots formed in each connector body and communicating with the respective opening to allow installation of the associated spinal instrumentation therein;   at least four connectors with means for attachment to selected portions of the patient's spine spaced longitudinally and laterally from each other;   at least two connectors having a pair of arms projecting laterally from the respective connector bodies; and   an elongated member sized to be received within the openings of the connectors with the pair of arms.